Over the past decades, the integration density of circuit elements in semiconductor devices and integrated circuits has rapidly grown and an end towards this trend is neither in sight nor to be expected in future. More and more functionality comprising different kinds of circuits, such as logic circuits, power devices, analog circuits, signal processing circuits etc. are integrated on a single chip. To achieve high integration densities, the different circuits comprised in an integrated circuit are often in close proximity to each other and may hence disturb each other's operation. Guard structures may be employed to shield different circuits or different circuit parts from one another in order to provide more reliable operation of the semiconductor device.